Apparatus for leveling and hardening sheet or strip material



Nov. 24, 1942. Y H. V. THADEN 2,303,096

APPARATUS FOR LEVELING AND HARDENING SHEET OR STRIP MATERIAL Original Filed March 21 1940 a Sheets-Sheet 1 "lmenfm': #572559 K fi/AWEM Y Nov. 24, 1942. H. v. THADEN 2,303,096 I APPARATUS FOR LEVELING min HARDENING SHEET 0R STRIP MATERIAL original File d march 21, 1940 a Sheets-Sheet 2 FIG. :1.

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Nov. 24,1942. v. D N 2,303,096

APPARATUS FOR LEVELING AND HARDENI-NG'SHEET 0R STRIP MATERIAL Original Filed March 21, 1940 3 Shgets-Sheet 3 Patented Nov. 24, 1942 APPARATUS FOR, L EVELING AND HARD-EN- IN G 'SHEET OR STRIP'MATERIAL Herbert V. Thaden, East Grand. Rapids, Mich. Original application March 21, 1940, Serial No.

Divided and this 1941, Serial No. 392,806

9 Claims. (01. 153-54) The present invention is a division of my application Serial No. 325,257, filed March 21, 1940,

and relates to improved mechanism for flattening and temper-hardening commercial metal products such as strip, sheet or light gauge plate, and involves means for bending such work alternately, first in one direction and then in another, by a'continuing operation which causes the fibers of the metal to be strained alternately in compression and tension in such manner that plastic flow of the metal takes place without subjecting the metal at the point of bend to an abrasive or scoring action. Theforegoing is accomplished without pulling the work over fixed members of any sort.

The above and further features of the invention will be fully apparentjfrom the following detailed disclosure when read in'connection with the accompanying drawings, and the features of novelty will be defined with particularly in the appended claims.

The invention provides means for positively I motivating or feeding the material without ex-' erting a friction drag around forming devices; but out of contact at the point of bend in such manner that a free running sharp bend is made first in one direction and thenin the reverse dimotion, the magnitude of such reverse bending being suchthat the material is stressed in excess of its elastic limit.

Bending the metal alternately first in one di-- rection, then in another, in a continuous manner," desirably strains the m'etal'fibers first in tension and then in. compression, so that a plastic flow takes place without subjecting the metal at the point of bend to abrasive or restrictive action and without exerting a tension or pull on the work. This desirable mode of operation is obtained preferably by the use of thepressure belts or equivalent means hereinafter referred to,- in cooperation with large diameter drums, so as to secure a sufliciently' large arc of contactbetween the work and the drums to insure adequate traction or driving force which will effectively cause a freely running bend to be made.

A preferred embodiment of the invention is: illustrated in Figures 1 to 3'inclusive, and an alternative embodiment is illustrated in Figure 4'. Figures 5 to 8 illustrate modifications.

Referring first to Figures 1 to 3 inclusive, I represents a suitable base frame which supports near one end bearings I 2 and M in which are"- journaled larger diameter drums l and I8. The bearings I4 are adapted to be adjusted relatively to the bearings [2, a feed" screw26 or its application May 9,

equivalent being illustratedforthe purpose. By so adjusting the bearings 14 relative to the bear ings I2. the sharpness of bend of sheet or strip material" trained over therolls' can be Varied.

The drums I6 and [8 are driven in the same direction by means of worms 22' and 24 carried on a shaft 26; said worms. meshing with Worm wheels 28 and 30 secured to the drum shafts as shown.

As' illustrated in Figure 3-, at the left end of the supporting base there is another pair of drums 32 and 34 driven respectively'by worms 36 and 38 and worm wheels 40 and 42, the worms 36 and 38 being of a pitch reverse to that of'worms 22 and 24 so as to rotate the drums 32 and 34in a directioncontrary to the direction "of rotation of drums l6 and I8. j

Disposed in the space gap between the peripheries of drums l 5 and I8 there is a guide shoe Which is secured at each end to a respective extension 46 formed on a bracket 48. Above each shoe 44 there is a guide roll 50 journaled in bearing hubs 52 formed on the brackets 48. Each bracket 48 carries screws 5'4'which pass through suitableopenings in an overhead frame 56. Nuts 58 and 60 coact with screws 54 and the frame 56 in such a way as to provide means for vertically adjusting the position of'the shoe 44 and guide roll 50 relative to the drums l6 and I8.

The frame 56"carries near its ends guide rolls 62 and 64. A belt 66 is trained over the guide rolls 50, 62 and 64 as illustrated, so as to thus effectively maintain a substantial arc of contact betweenthe plate or strip of material M and drums l6 and I8. Between the drums 32 and 34 thereis similarly positioned a shoe 68 and a guide roller 10, both being carried by a bracket 12 a'djustably supported from an underframe l4.

and" .64 are provided,'and a belt similar to the belt 66 is trained over the guide rollers 10, 1-6 and 18 for maintaining a proper arc of con'tact'be tween the sheet or strip material M and the drums 32 and 34.

The'overhead frame 56 carries depending supporting rods 82 which slidingly engage upright columns 84 secured to the supporting base [0. In 'a similar manner, the underframe '14 is provided with depending rods 66 which slidingly engage upright columns 88; Thus the frames '56- and 14 can be relatively adjusted as a unit toward and from the pairs of drums associated therewith in a manner which will be readily ap-! parent. Y

fl'n the operation of the embodiment of the in .ENT or ies F the guide brackets 92 for the shoes.

vention shown in Figures 1 to 3 inclusive, it is manifest that as the strip material M is fed in the direction of the arrows thereon, the belt 66 will cause a substantial arcuate length thereof to make firm frictional contact with drums l6 and I8. In the space gap between the drums, the material will be bent on a sharp radius around the guide shoe 44. From the drums l6 and IS, the material will be directed-to engage the underfaces of rolls 32 and 34, and will be bent around the guide shoe 68 in a direction reverse to the bend around the shoe 44.

The apparatus as described is so constructed and arranged that the space gap between each pair of drums can be readily varied so as to adjust the sharpness of the bend made between them. For a similar purpose, the shoes 44 and 68 and their associated guide rolls can be elevated or lowered so as to adjust the position thereof relative to the drums. In this way, the sharpness of the bend can be adjusted with great precision. By the arrangement described, an acute bend of extremely small radius can be effected, as dis-' tinguished from the bend effected by rolls heretofore used.

As is apparent from the arrows on the drums in Figure 3, the first pair of drums I6 and I8 both rotate counterclockwise, while the drums 32 and 34 both rotate clockwise. This results in advancing the strip material continuously in the same general direction as the material passes over the first pair of drums and under the second pair, the same being held in proper driving contact therewith by the respective belts, as

shown.

It is contemplated that instead of using the guide belts shown, the arc of contact between the propelling drums and the work may be maintained by hydraulic pressure exerted on the face of the work exterior to the drums or by suction exerted on the face of the work adjacent the drums. It is also contemplated that the drums may be heated while treating certain materials; This can be accomplished by passing suitable products of combustion through hollow trunnions on which the drums are supported, or alternatively, electrical heaters could be incorporated in the drums (see Figures to 8).

In the modification of Figure 4, I have shown a successive series of pairs of coacting rolls wherein the rolls constituting each pair rotate in opposite directions so that they jointly advance the sheet or strip material M continuously through the apparatus in the directionof the arrows indicated.

Disposed between each adjacent pair of rolls there is a shoe 9!] and means are provided for vertically adjusting each in respective brackets 92. Cooperating with each shoe 90 are pairs of guide members 94 and 96 which are adapted'to be adjusted toward and from one another by an adjusting screw 98 threaded through said guide members and adapted to be manipulated by a hand wheel I00. The adjusting screw shaft 98 is provided with reversely threaded portions so that the guides 94 and 96 can be caused to approach and recede from the shoe 90 to thus control the sharpness of bend which the material makes around such guide shoe. The successive pairs of rolls shown in this figure are suitably supported by bearings adjustably mounted in window openings I02 of side-frame housing members I04 to the top of which is secured an overhead element I06 which carries certain of,

The guide shoe positioned in the space gap between adjacent drums, is extremely acute and approaches closely to the effect which would be attained by bending the work double. Such acute bending at an extremely small or sharp radius is accomplished in my improved apparatus without the detrimental scoring or abrasive action which is inherent in apparatus dependent upon pulling or tensioning the work in order to flex the same over fixed knife edges or the like. The sharp bending accomplished by my improved apparatus ,takes place sequentially or progressively throughout all successive portions of the strip as a result of the forward feeding action made possible by the large arc of contact between the work and the large drums, thus positively feeding the work without exerting a tension drag over the fixed members which would be likely to cause the objectionable abrasion or scoring above referred to, on the surface of the work.

The apparatus described and claimed permits accurate control over the magnitude of stresses imposed on the material under treatment. This is particularly advantageous in cases wherein the yield strength or the starting point of plastic flow in the material is a high percentage of its ultimate strength. By the utilization of the invention described, any tight spots in the metal are caused to disproportionately stretch and thus equalize themselves in length with respect to adjoining loose spots. Furthermore, the method is effective to alternately subject the grains of the metal to strain deformation in tension and compression and thus impart to the metal increased hardness known to those skilled in the art as temper.

Figure 5 is illustrative of a modification for holding the strip or sheet in contact with the large drums I6 and I8 by means of either pressure or suction; For example, pressure may be applied through th pipe P or suction applied through the pipe P Such pressure or suction may be developed in the volumetric space by placing a dam member or end plate P on each side of the strip or material under treatment. If desired, additional means may be provided to maintain a generous arc of contact between the work and the drums Hi and i8, by mounting a multiplicity of rollers P in juxtaposition to the drums, as shown.

Figure 6 illustrates a modification in which the drums l6 and la are arranged to cooperate with belts M and N, trained over suitable guide rolls; as shown, above and below the drums. In this modification the strip is uncoiled from a reel R passing freely around the blade 44 and wound up on the reel R. After a predetermined amount of material has been accumulated on the reel R, it will then be uncoiled therefrom, coming in contact with the lower side of the rolls l5 and It, as indicated by dotted lines in the drawings. At this time the pressure belt B and its guide rollers will be properly positioned to compel the sheet or strip of material to traverse the sinuous path,

as indicated. Duringisuch'reverse movement the blade will be arranged in an inverted position to that showriin full lines, the blade in this instance being detachably mounted in any suitable manner. n v

Figure"? illustrates a further variation in the inethod of effecting a sharp, free running bend. In this modification, the endless power-driven belt is guided around a plurality of guide rollers s and cooperates with an .idle belt V'which is trained, around a plurality of guide rollers W. Adjustable platens T and U mounted in juxtaposition to a fixed guide shoe W; serve to positively feed or motivate the'strip to form the acute free'running bendand thus stress the material beyond its elastic limit, as will be understood.-

' Figure 8 shows diagrammatically heating elements Hincorporated in the rolls W and I8 for ellectivelylowering the yield point of the strip by moderately heating the drums internally so as to I thus facilitate the flattening operation and equalize the tight and loose spots or areas of the strip or sheet.

Itwill be apparent to those versed in the art of metal rolling, stretcher'leveling, and the like; that the apparatus herein described provides for overcoming inherent weaknesses or disadvantages in the processesand mechanisms heretofore available. For example, in the known process of stretcher leveling of high tensile stainless steel or other similar materials, the metal must be stressed in tension to a point closely approaching its ultimate strength in order to effect any appreciable plastic flow. At such loading of the metal, the variations of the pressure and fric tion of the stretcher leveler generally induce far greater stresses and inequalities in the plastic flow of the material than those originally present.

- For this reason stretcher leveling has proven inadequate on high strength materials or materials having a high ratio of yield strength to ultimate strength.

Heretofore it has been proposed to roller level sheets, strip and the like, but such rollertreatment has been found impractical or inefiective for the reason that any practical size rollers are too great in radius to cause a sufficiently sharp bend in the metal to stress it beyond its yield point and thus effect the required plastic flow of the metal. In a prior application, Serial No. 282,918, filed July 5, 1939, now Pat. No. 2,275,095, dated March 3, 1942, I have disclosed'a method and means involving the use of small radius knife-edged teeth defining a sinuous pass through which the metal travels. The effectiveness of such prior method and apparatus has been demonstrated in practice, and is limited only by the fact that the surface of the metal to be fiattened is occasionally scored because of the abrasive action brought about by the tension drag of the material. The present invention provides means for overcoming this scoring, and provides an improved mechanism which is effective to subject all portions of a strip, sheet or plate to a controlled bending action at a very acute angle in the continuous manner. I thus avoid the abrasive or scoring action inherent in prior devices involving the pulling of the metal over toothlike fixed members.

I claim: i

1. Apparatus for flattening and working metal strip or sheet material, comprising a pair of adjacent large diameter drums rotating in the same direction, a guide shoe in the gap therebetween, a flexible traveling member, and guide rollers,

one in said gapand one adjacent each said drum effective to maintaina substantial arc of contact between said material'and said drums and ends itaroundfsaidshoe. 2; Apparatus-for flattening and working metal strip or sheet material, comprising a pair of 'adj'acentdarge diameterdrums rotating in the same direction,-aguidejshoe in the gaptherebetween, a flexible traveling-member eliective to maintain a substantial-arc of' contact between said-material and both "said drums and guide it" around said shoe, and three guide elements constituting supporting means forsaid traveling member, one being located in the gap between said drums and the other two being" located on opposite -sides thereof beyond said drums, said flexible member traveling'around said three elements and cooperating with "said drums to maintain said are of contact.

' Apparatus forfl'attening and working metal strip or sheet material, comprising a pair of ad- I jacent largediameter drums rotating in the same direction, a guide shoe therebetween, a traveling belt effective to maintain a substantial arc of contact between said material and said drums and guide said material around said shoe, a guide roll 7 adjacent said shoe, other rolls over which said belt travels to maintain a substantial arc of contact between said material and said drums, and means for adjusting the first named roll and said shoe with respect to said drums.

5. Apparatus for flattening and working metal strip or sheet material, comprising a pair of adjacent large diameter drums rotating in the same direction, a guide shoe therebetween, a traveling belt effective to maintain a substantial arc of contact between said material and said drums and guide said material around said shoe, a guide roll adjacent said shoe, other rolls over which said belt travels to maintain a substantial arc of contact between said material and said drums, a normally fixed support spaced from said 'drums, and one bracketadjustably secured thereto supportingsaid guide shoe and said first named guide roll, and other brackets secured to said support and carrying said other rolls.

6. Apparatus for flattening and working metal strip or sheet material, comprising one pair of drums rotating clockwise and another pair of drums rotating counter-clockwise, a respective guide shoe between the drums of each pair, a respective endless flexible traveling member eifective to maintain a substantial arc of contact between said material and each pair of drums andguide said material around the respective shoe coacting therewith. and separate sets of guide rolls over which each flexible member is trained.

7. Apparatus for flattening and working metal strip or sheet material, comprising one pair of drums rotating clockwise and another pair of drums rotating counter-clockwise, a respective guide shoe and roller adjacent thereto between the drums of each pair, other guide rollers adjacent each of said drums, a respective endless flexible belt traveling around'the roller adjacent said shoe, and other rollers adjacent said drums and effective to maintain a substantial arc ofcon tact between said material and each pair of drums and guide said material around the respective shoe coacting therewith, and the respective sets of guide rollers for said belts being so positioned and supported with respect to said shoes and said pairs of drums that the material is continually advanced in the same general direction while maintained in contact with substantial arcs of oppositely disposed peripheral portions of said pairs of drums.

. 8. Apparatus for flattening and working metal strip or sheet material, comprising one pair of drums rotating clockwise and another pair of drums rotating counter-clockwise, a respective guide shoe and guide roller between the drums of each pair, other rollers adjacent said drums a respective flexible member trained around a set of said rollers associated with each shoe and each pair of drums and effective to maintain a substantial arc of contact between said material and each pair of drums and guide said material around the respective shoe coacting therewith,

respective traveling belts sopositioned and supported with respect to said pairs of drums that the material is continually advanced in the same general direction while maintained in contact with substantial arcs of oppositely disposed peripheral portions of said pairs of drums, and an adjustable mounting for one of the said guide rolls. I I

9, Apparatus for flattening and working metal strip or'sheet'material, comprising a pair of adjacent large diameter drums rotating in the same direction, a guide shoe therebetween, one guide roller adjacent said shoe and one other guide roller adjacent each of said drums, a flexible traveling member trained around said rollers and nets iective to maintain a substantial arc of contact between said material and said drums and guide said material around saidshoe, and respective bearings for the drums of each pair, the bearings for at least one drum being adjustable so as to permit variation of the spacing between said drums, the said shoe androller adjacent thereto being carried by an adjustable support adapted to permit variation of the positions thereof inthe space between said drums; I v a HERBERT V, THADEN. 

